The invention relates to an electrical component support on a printed circuit board with a metallic layer supporting body, on which a flat insulating layer is provided. The printed circuit board elements are provided on this insulating layer and the printed circuit board elements have individual metallic tracks for the connection of leads from the electric components.
Commonly printed circuit boards, particularly printed circuit boards having a metal layer (metal PCB's or Printed Circuit boards), have their electric components mounted by means of Surface-Mounted Device Technology (SMD). In this case, the electric components are directly glued onto the flat circuit board metallic layer without any insulating interlayer connection. The leads on both sides of the electrical component, along with the corresponding contact surfaces of the printed circuit board, are then moved through a soldering bath where the leads are connected with the printed circuits. In the case where several electrical components are utilized, the leads must be bent before the soldering process takes place. In every case of metal PCB's of this type, the overall heights of the components (such as transistors, Hall-IC's, etc.) have their full effect on the overall height of the device for which the circuit board is to be used on the side containing the component; for example, the overall height of an electric motor is increased by the height of the component(s).
In addition, it is quite expensive to precisely position the flat-placed electric components on the circuit board. In order to avoid a bending of the leads of the electric component, it is known to correspondingly punch holes into the metal PCB. The resulting punched edge is not desirable because the edge can permit damaging of the insulation of the leads which could actually short circuit a part or portion of the system. Additionally, the absence of the punched-out metal of the printed circuit boards due to the punched-out holes, results in a higher leakage flux, particularly for magnetically sensitive electrical components.
The invention is based on the object of providing a printed circuit board of the initially mentioned type which, without any special expenditures, allows for a precise mounting of the electrical component on the circuit board, which mounting is held constant and fixed for a long time, is resistant to changes in temperatures at the circuit board, and of the electric components. This is particularly true when the electrical components are sensors, such as rotor rotation detectors. Also of concern is the relative and exact positioning of a plurality of sensors to one another as well as to a motor rotor and to obtain this positioning at a cost-reducing mounting.
This object is achieved by utilizing a printed circuit board having a metallic layer supporting body on which a flat insulating layer is provided and with a layer having individual metallic tracks being provided on this insulating layer for the connection of electric components, and wherein there is at least one depression impressed into the printed circuit board for accommodating electric components.
In accordance with the invention and for a further reduction of the axial overall height of electric motors, impressions are made in the printed circuit board which open in the direction of the rotor flange and wherein the electric components are placed into these impressions. In addition, the impressions offer protection to the electric components, to the soldered ends of the power leads and to other components.
The precise fixing of a component is made possible by its resting against cut edges of the recess formed by the impression. The invention makes it possible to fit, for example, a Hall-IC into the impression of the low-retentivity printed circuit board in such a manner that an increased magnetic short-circuit for the Hall element (Hall generator or Hall IC) results in a larger signal deviation (output voltage). The insulation layer of the printed circuit board can shield against any undesirable leakage flux.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.